Refrigerating apparatus



y 7, 1959 J. WEIBEL, JR 2,893,626

REFRIGERATING APPARATUS Filed Dec. 27, 1956 Fig/ INVENTOR. John We/be/ Jr.

BYiz szg I H119 A/forn ey United States Patent REFRIGERATIN G APPARATUS John Weibel, Jr., Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 27, 1956, Serial No. 630,821

2 Claims. (Cl. 230-232) This invention relates to refrigerating apparatus and more particularly to a built-in muffler arrangement in a hermetically sealed motor-compressor unit. It has been common practice to provide mufflers at the inlet of a refrigerant compressor for the purpose of muifiing the noise produced by the refrigerant handled by the compressor. These mufflers have added considerably to the cost of the motor-compressor units not only because of the material required for making the mufiler but also because of the cost of attaching the mufilers to the compressor.

It is an object of this invention to eliminate both of these costs by utilizing the interior of the motor rotor as a muffier.

More particularly, it is an object of this invention to provide a motor-compressor unit in which the gas to be compressed flows through the motor rotor and in which the interior of the motor rotor is provided with a series of interconnected mufiiing chambers.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure l is a vertical sectional view showing the invention applied to a motor-compressor unit of the type disclosed in copending applications S.N. 517,603 filed July 23, 1955, now Patent No. 2,855,139, and S.N. 549,713 filed November 29, l955, now Patent No. 2,844,302;

Figure 2 is a plan view, on a reduced scale, of the motor rotor; and

Figure 3 is an elevational view, on a reduced scale, showing the motor rotor core.

Referring to the drawing wherein a preferred embodiment of the invention has been shown, reference numeral generally designates the outer shell for enclosing the motor and compressor assembly generally designated by the reference numeral 12. The casing 10 consists of an upper inverted cup-shaped member 14 which serves as the main support for the motorcompressor assembly and a lower cup-shaped element 16 which is welded to the element 14 along the line of juncture 18. The motor compressor may be supported within the inverted cup-shaped member 14 in any suitable manner such as by means of mounting brackets 24 The compressor comprises a pair of pistons 42 and 44 which operate in pumping chambers 46 and 48, respectively, formed in the lower portion of the main casting or frame 24. These pistons are adapted to be reciprocated by means of connecting rods 40 which cooperate with an offset crank-like portion 39 formed on the drive shaft 30. For purpose of illustration there is shown a two-cylinder reciprocating compressor where- 7 as this invention is equally applicable to other types of COIDPI'GSSOI'S.

2,893,626 Patented July 7, 1959 For a more complete description of the manner in which the compressor assembly is supported Within the outer casing and the construction and operation of the compressor, reference is hereby made to said copending application S.N. 517,603 which more fully describes the compressor apparatus shown herein.

A main casting 24 is supported on the mounting brackets 20 and is carried by the casing element 14 and serves to support a conventional motor stator 26 and also to support a shaft bearing 28 in which the main drive shaft 30 is journalled. A motor rotor 34 includes a laminated outer portion which is supported on the upper end of the drive shaft 30 by means of a cast core or hub portion 36. As best shown in Figure 2 of the drawing, the outer portion of the motor rotor 34 is made of laminated metal in accordance with conventional practice but is provided with a larger than usual central recess 38, the diameter of which is considerably greater than the diameter of the drive shaft 30 so as to provide room for the core element 36 which serves to support the outer laminated portion of the motor rotor on the shaft 30. The element 36 is provided with a press fit on the shaft 30 or may be keyed to the shaft 30 so as to provide a driving connection between the motor rotor 34 and the shaft 30. The central recess 38 of the laminated portion of the rotor 34 is provided with a pair of oppositely disposed axial grooves 40 and 41 which serve as gas passages for a purpose to be more fully described hereinafter.

The gas to be compressed is supplied to the motorcompressor unit through the suction line 52 which is provided with a screen or filter element 54 at the point where the gas enters the motor-compressor housing 10. The gas then flows upwardly between the housing 10 and the motor stator 12 and is required to flow downwardly through the motor rotor on its way to the passage 56 which conveys the gas from the lower end of the motor into the conventional suction chamber 58 formed in the cylinder head 60.

As shown in the drawings, the motor rotor core element 36 is provided with a pair of circumferentially extending cutaway portions or grooves 62 and 63 which form muffler chambers for the gas as it flows through the motor rotor. For purposes of illustration two grooves have been shown whereas the number of grooves and the sizes of the grooves may be varied without departing from the spirit of my invention. Insofar as certain aspects of the invention are concerned the mufller chambers could be formed in the laminated portion of the motor rotor but for practical reasons the chambers have been formed in the manner shown.

As shown in Figure 3 of the drawing, a first plug-like element or stopper 64 is secured to the upper end of the core element 36 so as to plug the entrance to the upper end of the one groove 40 in the motor rotor portion 34 and is provided with a second and similar plug portion 66 adjacent its lower end for plugging the lower end of the other cut-away portion 41. By virtue of the construction thus described, the gas to be compressed enters the motor rotor through the upper end of the passages 41 and is fed downwardly until a portion of the gas flows into the first of the muffler chambers and another portion of the gas flows into the second of the muffler chambers before it leaves the bottom end of the motor rotor through the lower end of the passage 40. The gas is then fed into the inlet 56- of the compressor so as to be compressed and thereafter flows into the outlet passage 70 which connects with the 0 compressor discharge line 72 for conducting the com- By virtue of the above described arrangement it is obvious that the motor rotor itself constitutes an inlet mufiler and that the arrangement disclosed herein eliminates the need for connecting a separate muliler in the gas line.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a sealed motor-compressor unit, a main frame including a compressor having a suction inlet, a motor supported by said frame and including a drive shaft opertively connected to said compressor, said motor comprising a stator carried by said frame and a rotor disposed within said stator, said rotor having a plurality of internal mufiling chambers therein, said rotor comprising an outer laminated portion provided with an axially extending passage in its inner periphery and an inner core portion having said internal mufiling chambers formed in its outer periphery in communication with said axially extending passage, said core portion having a central aperture receiving said drive shaft, and means including a housing surrounding said motor-cornpressor unit directing a gas to be compressed through said muflling chambers and thereafter into said inlet.

2. In a sealed motor-compressor unit, a main frame including a compressor having a suction inlet, a motor supported by said frame and including a drive shaft operatively connected to said compressor, said motor comprising a stator carried by said frame and a rotor disposed Within said stator, said rotor having a plurality of internal muflling chambers therein, said rotor comprising an outer laminated portion provided with a pair of oppositely disposed axially extending passages in its inner periphery and an inner core portion having said internal mufiling chambers formed in its outer periphery in communication with said axially extending passages, means for closing the upper end of one of said axially extending passages and means for closing the bottom end of the other of said axially extending passages, said core portion having a central aperture receiving said drive shaft, and means including a housing surrounding said motor-compressor unit directing a gas to be compressed through said muffiing chambers and thereafter into said inlet.

References Cited in the tile of this patent UNITED STATES PATENTS 658,100 Wood Sept. 18, 1900 704,975 Sessions July 15, 1902 1,039,110 Finch Sept. 24, 1912 1,187,031 Black et al. June 13, 1916 1,911,128 Apple May 23, 1933 1,954,002 Tursky Apr. 10, 1934 1,998,604 Belden Apr. 23, 1935 2,072,307 Kenney Mar. 2, 1937 2,113,967 Stephenson Apr. 12, 1938 2,283,024 Wolfert May 12, 1942 2,670,894 Warrick et al. Mar. 2, 1954 2,752,088 Borgerd et al. June 26, 1956 2,836,349 Scheldorf May 27, 1958 

